Recently, a cell phone for performing a Bluetooth communication method is well known. In accordance with spread of this type cell phone, an in-vehicle hands free device is disclosed in, for example, JP-A-2003-198713 (corresponding to US 2003/0114202) and JP-A-2003-218996. The hands free device communicates with the cell phone by using a Bluetooth communication link.
When the cell phone and the hands free device are coupled with each other by the Bluetooth communication link, the cell phone receives a reception signal from a communication net work, and the in-vehicle hands free device receives the reception signal from the cell phone. Then, the in-vehicle hands free device starts to control the cell phone. For example, the hands free device informs a passenger in a vehicle of reception of the reception signal, and the device prohibits output of a ring tone of the cell phone. On the other hand, an in-vehicle navigation device capable of connecting with multiple communication devices is developed, and further, an in-vehicle navigation device having a hands free function is also developed.
An in-vehicle navigation device includes a data communication module and a Bluetooth communication element. The data communication module has a cell phone function for communicating with multiple communication devices. In this navigation device, when the Bluetooth communication element is coupled with a cell phone by using a Bluetooth communication link, a starting trigger for communicating with voice may be generated by the data communication module. In this case, after the Bluetooth communication element cuts the Bluetooth communication link between the element and the cell phone, the data communication module starts to communicate with voice. After the data communication module starts to communicate with voice, the navigation device cannot receive a reception signal from the cell phone even when the cell phone receives the reception signal from the communication network. Accordingly, the navigation device cannot control the cell phone not to output a ring tone of the cell phone.
In this case, the cell phone independently receives the reception signal from the network, and outputs the ring tone even though the data communication module communicates with voice. Thus, the passenger has to operate the cell phone by himself to stop the output of the ring tone. Therefore, it is necessary for the passenger to operate the cell phone additionally.
Accordingly, it is required for the in-vehicle hands free device to improve convenience for the passenger.